Question

Find the values of x and y if a and b are in inverse proportion:

1. 12 x 8
2. 30 5 y

Answer 1

In an inverse proportion,

When we multiply the first quantity by any constant k, then the another quantity is divided by the same constant k.

Given, 

a	12	x	8
b	30	5	y

Here, we see that in part (b), when we divide 30 by 6, we will get 5.

So, in part (a), we will get the value of x.

i.e. x = 12 × 6 = 72

Similarly, in part (a), when we divide x i.e. 72 by 9, we will get 8.

So, in part (b), we will get the value of y.

i.e. y = 5 × 9 = 45